Magic Microphone Problems

I am having trouble with my Magic Microphone. When I use it now it only lasts for 4 or 5 songs then everything goes haywire.
The sound disappears and becomes merely an echo and I am unable to select songs after it happens. The words and pics from the song that was playing stays on the screen even after everything is unplugged.
Anybody have any idea on what is wrong or how it can be fixed.
Thanks